AQUATIC FACILITIES
Gas bill shock triggers revolution in energy-efficient aquatic centre design by Poppy Johnston, The Fifth Estate (www.thefifthestate.com.au)
Poppy Johnston, journalist with The Fifth Estate, has been looking into the impact of rising energy costs on council owned and operated aquatic centres - and what can be done to help improve energy efficiency and reduce the environmental impact and operating costs of these critical public infrastructure assets. As Australian councils struggle to pay sky-high gas bills to heat and cool their aquatic centres, pressure is building to find cheaper and less carbon-intensive ways to keep these treasured community facilities open. Australia might be a leader on building energy performance, but one niche building type appears to have largely fallen through the cracks: the local aquatic centre. According to experts, historically cheap gas prices and the absence of a carbon tax has spawned a fleet of energy-hungry aquatic facilities across the country. These facilities, which typically consist of indoor pools and other functions such as gyms and cafes, can consume up to seven times more energy per floor area than the average commercial office building. This could soon change, with councils now facing enormous bills thanks to rising gas prices that aren’t expected to decline. One source from a metropolitan Victorian council told The Fifth Estate that the council’s energy bill had increased by more than 60 per cent compared with 2014-2017 averages. Fortunately, there’s growing evidence to suggest it’s possible to design and retrofit aquatic centres to dramatically improve energy efficiency. Northern Environmental Design director Jonathan Duverge, whose PhD focused on energy efficiency in aquatic centres, says Europe leads the way on aquatic centre design. “Higher energy costs have prompted the design of better performing buildings,” he explains, “with, for example, minimal use of glass.” “It’s very rare to see an aquatic centre with floor-to-ceiling glass surrounding it… Europe is really looking at the design,” he said. By contrast, large swathes of glazing are common in Australian 16
Construction Engineering Australia • Feb/Mar 2020
aquatic centres. While it might look attractive, sky lights and floor-toceiling glazing attracts condensation. If not managed correctly, glare can also be dangerous inside an aquatic centre. Steel framing is also common in Australian aquatic centres, creating thermal bridges and attracting condensation and rust. Duverge says that in Australia it’s rare for designers to consider how much energy the facility is going to use – it’s all about making them “tall and shiny”. “It doesn’t help that fully-glazed domes are recognised by the industry as tender-winning designs,” he adds. He says also people don’t understand the effect of evaporation and heat loss that occurs in an indoor pool. “They treat it as an office building.” He says the evaporative effect has a big impact on energy consumption, but is rarely taken into consideration. “I think people just try to do calculations in terms of heating but neglect the effect of evaporation. That’s not really accurate.” Another common problem is that aquatic centre staff are not trained or don’t understand how HVAC systems work, opening windows and doors when it becomes too hot rather than adjusting the HVAC. Duverge is seeing change in the industry as councils start to feel the financial and ethical pressure, with many declaring a climate emergency and looking for opportunities to decarbonise their operations.
CAPTURING HEAT ENERGY For RMIT senior industry fellow Alan Pears, an energy efficiency expert who’s been looking into the energy performance of aquatic centres since the 1990s, the key issue for aquatic centres is that they flush out enormous amounts of heat energy that is costly to produce. Most of the thermal energy going into an aquatic centre is used to heat the air around the pool, followed by the pool water itself which is heated to around 27-29 degrees Celsius. The warm water from the pool evaporates, absorbing large amounts of energy, producing water vapour and making the pool facility hot and steamy.
